Single action magnetos



Sept. 4, 1962 D. E. RICHARDSON SINGLE ACTION MAGNETOS Filed March 8, 195? FIGJ.

0. E. RICHARDSON By M INVEN TOR ATTS United States Patent 3,052,803 SINGLE ACTION MAGNETOS Donald E. Richardson, Chicago, 111., assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Filed Mar. 8, 1957, Ser. No. 644,959 3 Claims. (Q1. 310-35) This invention relates to an electromotive force generating device and more particularly to a one shot generator for providing a triggering signal for initiation of an explosive actuating device.

More particularly, the invention is directed to a magneto having a movable locked spring loaded armature which is adapted for release in response to a single mechanical actuation for effecting operation of the device.

A prior art type of magneto for electrically firing a detonator is shown in the US. Patent 2,703,530 to Me- Gee dated March 8, 1955.

It is a feature of this invention to provide a one shot magneto of improved design for providing a signal pulse for actuation of an electroresponsive explosive detonator.

One object of the instant invention resides in the provision of a cocked trigger type actuator for a one shot type magneto.

Another object relates to an arrangement of an armature associated with a coil of the device which is adapted to move from an initial position of maximum flux density adjacent a pole of one magnet, away from said magnet to a position of maximum flux density with respect to one of the poles of a second magnet.

Still another object resides in the use of a pair of juxtaposed magnets and a common armature and coil assembly in an improved magneto which is highly efficient and is of simple construction.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing wherein:

FIG. 1 is a view, partly in section, of a magneto of the instant invention connected to a detonator; and

FIG. 2 is a perspective view of the device of FIG. 1.

Referring now to the drawing and more particularly to FIG. 1, a malgneto device according to the instant invention is generally indicated at 1. The magneto 1 comprises a pair of side plates 2 which are maintained in a fixed spaced relation by a plurality of spacers 3 which are clamped by suitable retaining means such as through bolts 4 as shown in FIG. 2. A pair of horseshoe magnets 5 and 6 are disposed in canted relationship and retained as by machine screws 7. Movably disposed in the air gap between both pairs of adjacent poles of the two magnets is an armature 8 of a suitable material such as soft iron. It is mounted for movement between the lateral undercut guides 25. A coil 9 is disposed centrally about the loosely pivotally mounted armature 8 substantially as shown at 24.

A triggering and actuating mechanism generally indicated at 10 comprises a plunger assembly 11 having a piston or head portion 12 and a rod extention portion 13. Disposed about the rod portion of the plunger and abutting the rear side of the piston head 12 is a loading spring 14. The spring 14 is restrained at the opposite end 15 thereof by a guide bushing 16 which is mounted to the top plate 17 and which provides a bearing for the piston rod 13.

The guide bushing 16 extends through the top plate 17 and provides a stop for the terminal end 18 of the plunger assembly. The terminal end is provided with a screw 19 and washer 20 which engages the stop end of the bushing 16. The rod portion 13 is also provided with Patented Sept. 4, 1962 an undercut groove 21 of reduced diameter for reception of the trigger ann fork 22 which locks the piston in a spring loaded condition.

In operation the trigger arm fork 22 is disengaged from the groove 21 and plunger assembly 12 moves due to the release of the stored energy of the spring 14 to move the armature from an initial position of maximum flux density with respect to magnet 5 to a position of maximum flux density with respect to magnet 6 as shown by the broken line construction on FIG. 1. This provides for the generation of a desired electrical signal due to flux changes occurring in the coil 9 with armature travel and fires detonator 23.

Whereas in the illustrated embodiment of the invention the armature and pole elements are each shown as a unitary structure, it will be understood that this has been done by way of example only, and that, if desired, these structures may be of laminated construction to control the effects of eddy currents therein.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as sepcifically described.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A magneto device comprising a housing, a pair of horseshoe shaped magnets disposed within said housing in a canted juxtaposed relation with the poles thereof in mutually spaced adjacency, the adjacent poles being of opposite polarity, a coil disposed in the flux paths of each of said magnets, a movably mounted armature extending through said coil and being normally in an initial position in contacting relation with both pole faces of one of said magnets, said armature being movable to a final position into contact with both pole faces of the other of said magnets, guide means for said armature, and means for quickly moving said armature between said initial and final positions.

2. The device of claim 1 further characterized by said armature moving means comprising a plunger slidably mounted in said housing, spring means for urging said plunger against said armature for contemporaneus movement thereof, and releasable means for normally re straining said plunger in a position to bias said spring to a preloaded condition and effective upon release thereof to permit quick movement of said armature by said plunger thereby to effect the generation of an electrical signal with movement of said armature.

3. A one shot magneto comprising a coil disposed about an armature which is movable in a field between adjacent poles of opposite polarity of two permanent horseshoe shaped magnets, said poles being positioned in a canted juxtaposed mutually spaced relationship, a normally restrained spring loaded plunger disposed in adjacency to said armature for quick movement thereof between said adjacent poles when the energy stored in said spring is released, and means normally retaining said plunger in a biased condition and releasable therefrom by a single linear movement thereof for release of said plunger.

References Cited in the file of this patent UNITED STATES PATENTS 2,533,136 Muldoon Dec. 5, 1950 FOREIGN PATENTS 468,169 Great Britain June so, 1937 OTHER REFERENCES Societa Anonima Pignone Officine Meccaniche. 

